Drive for motor vehicles



Nov. 19, 1929. J. w. CHRISTIE 1,736,391

DRIVE FOR MOTQR VEHICLES Filed Feb. 25, 1929 4 Sheets-Sheet l FIG].

Sww'emioz Q Nov. 19, 1929. J. w. CHRISTIE 7 1,736,391

DRIVE FOR MOTOR VEHICLES 1929. J. w. CHRISTIE 3 ,391

DRIVE FOR MOTOR VEHICLES Filed Feb. 25, 1929 4 Sheets-Sheet 5 '.FIG.4.

Swwemtoz K Jbkn PizZZ'er Ckrvbzie 1929. J.W. CHRISTIE 1,736,391

DRIVE FOR MOTOR VEHICLES Filed Feb. 25, 1929 4 Sheets-Sheet 4 v Q Ijwue-nio-L J'ahn Plalier- Gkrdsiie name Nov. 19, 1 1929 UNITED STATESPATENT OFFICE JOHN WALTER CHRISTIE, OF AVON, NEW JERSEY, ASSIGNOB, BYMESNE ASSIGNMENTS, 'IO BROWNING CRANE COMPANY, OF CLEVELAND, OHIO, ACORPORATION OF OHIO DRIVE FOR MOTOR VEHICLES Application filed February23, 1929. Serial N'o. $42,003.

It has been proposed heretofore to mount four wheels on a sin le deadaxle and drive them in pairs throng live axle sections. In suchconstruction two wheels are mounted son each side of a vehicle andjournaled in a rigid carrier which in turn is j ournaled on the deadaxle so that it may rock and thereby permit the wheels of the pair toadapt themselves to irre ularities in the terrene. With 10 this carrierasbeen associated means for driving the wheels of a pair simultaneouslyfrom a single live axle section.

The im roved drive embodies some of the charactenstics of the knowndrive referred to above but difiers therefrom in several importantrespects whereby greater traction is secured, torque reactions areequalized, unsprung weight is reduced to a minimum and "-2 greaterefliciency and a reduction in the stresses on the units areaccomplished.

In accordance with the invention there is provided an eight wheel drivein which the wheels are mounted inpairs on opposite sides of thevehicle, two pairs bein on each side and the two pairs on each si ebeing so related as to insure a better distribution of the load and anequalization of the stresses impressed on'the units. Not only are thetorque reactions balanced by the improved disposition of wheels anddriving elements but stresses arising from side sway and irregularitiesin the terrene are also effectively counteracted by mutual interaction;

An important object of this inventionis the provision of an eight wheeltraction structure and drive mechanism comprising a four wheel unit oneach side of the chassis adapted for interchangeable connection with anendless track, whereby the vehicle is convertible from a road vehicle toone of the caterpillar or track-laying type as desired.

Other advantages of the improved drive will appear more clearly as thedescription 'proceeds, among which may be noted minimum unsprung weightand the advantageous \disposition of antifriction'bearings for all ofthe rotating parts in the drive.

Reference is now to be had to the accompanying drawings which illustratesomewhat conventionally a motor vehicle chassis to which the improveddrive has been adapted and wherein:

Fig. 1 is a View in side elevation of such a vehicle, a part of thecarrier being broken away to show the relation of the driving gears forone set of wheels.

Fig. 2 is a view in plan of the vehicle shown in Fig. 1.

Fig. 3 is'a fragmentary view in section and on a larger scale showingthe final drive gear and the relation thereto of one of the live axlesections and of the dead axle whereby the carrier at one side of thevehicle is sup-' ported for rocking, the view being taken on the planeindicated by the line 3-3 of Fig. 2 and looking in the direction of thearrows.

Fig. 4 is a view in horizontal section through a portion of the carriershown in Fig. 1 and taken on the plane indicated by the line 44 andlooking in the direction of the arrows. v

Fig. 5 is a side view of the rear wheels of a vehicle with trackattached.

Fig. 6 is a plan view of a portionof the track, showing the twocomplemental connecting links. I

and

Fig. Sis a section taken on the line 8-8 of Fig. 6.

The improved drive, which may be adapt-' Fig. 7 is a section on line 7---7 of Fig. 6; l

the function of propelling it are advantageously discharged. The loadcarrying axle is indicated at 6 and is enlarged centrally to receive thefinal drive transmission gearing 5, its associated bearings 7 andreduction gearing 8 when employed. The springs 9 for the vehicle arecarried by the load.

rier A and associated transmission mecha' nism. This carrier comprisesgenerally two sections a, b,wl1ich are bolted together as indicated at12, one section a having a tubular extension 13 which is journaled onthe tube 11 and the other section I) having an aligned, oppositelyextendin tubular extension 14 which receives antifriotion bearings 15for the purpose to be described. The general outline of the carrier Ais-indicated in Fig. 1.

Vith the carrier A supported at its midsection on the load carryingmember 6, in the manner described, provision is made for supporting thevehicle wheels in the carrier in advantageous relation toone another fordriving and load carrying purposes. As indicated in Fig.2 four wheelsare provided at each side of the vehicle with the result that an eightwheel drive is afforded. For the purposes of this specification the fourwheels at one side only will be described since they are duplicated atthe other side of the vehicle. The wheels B and B, which are supportedon a common stub axle,-wil1 be hereinafter referred to as constituting apair as will be the wheels C and C, which are likewise journaled on acommon stub axle. The axle for the Wheels C and O is indicated at 16 inFig. 4. This stub axle is journaled in the carrier A by means ofantifriction bearings 17, 18, supported respectively, in

the sections a, b, of the carrier. By this disposition the wheels C, C,are mounted symmetrically on opposite sides of the carrier and in themost advantageous load carrying relationship. The pair of wheels B, B,are similarly mounted on a single stub axle 19 at the other end of thecarrier, the two axles being spaced equidistant from the center line ofthe load carrying axle 6. Since the carrier A is free to rock about theload carrying axle 6 it will be clear'that the respective pairs ofwheels are free to follow irregularities in the terrene. By providingfour load carrying wheels at each side of the Vehicle the advantage ofeight points of support are secured, these advantages now beingrecognized in respect of traction, unit ground pressure, ridingqualitles, etc.

Stresses arising from side sway are mutually resisted by these eightwheelsand their respective bearings. By disposing the two wheels of eachpair in symmetrical relation to one another and to the respectivecarriers and by disposing the wheels before and bebind the load carryingaxle in symmetrical mony four wheels at one side of the vehic e insymmetrical relation to the four wheels of the other side, a completebalance and har-f are achieved in the su port of the load under alloperating conditions guild-unbalanced twist ng stresses on the chassisand driving parts are reduced to a minimum. The improved means forapplying driving power to the several wheels will now be described. g v

Within the load carrying axle 6 and its associated parts including thetube 11 and the tubular extensions 13, 14, of the carrier, all of whichparts are concentric and generally aligned, is journaled a tubular liveaxle mem-- ber 20. This section is journaled preferably in threeanti-friction bearings one of which 21 is preferably adjacent its innerend, another of which 15 is preferably adjacent its other end at a pointbeyond the carrier A and the third of which 22 is, preferably disposedsubstantially centrally of the carrier itself. The bearing 22 may besupported on a flange 23 formed on the inner face of the section A ofthe carrier as illustrated in Fig.3. On the live axle section 20 iskeyed a spur gear 24 by which the stub axles 16 and 19 are driventhrough similar gear trains. The gear 24 isv disposed within the carrierA and meshes with an idler gear 25 journaled in the carrier on anantifriction bearing 26. For lightness and in the interest of assemblingthe bearin 26 ma be supported on a tubular shaft 2 'exten ing throughthe sections of the carrier A and held in place by a flanged ring 28threaded thereto. The idler gear 25 meshes with the gear 29 which iskeyed on the stub shaft 16 for the wheels 0, C, splined thereon. Thetrain of gearing described is duplicated at the other side of the mastergear 24: in order to provide for driving of the other stub axle 19 onwhich are splined the other pair of wheels'A, A. I

The drive described insures the positive transmission of power from thelive axle sections to the four wheels at the side of the vehicle end androtation at equal speeds. All of the rotating members are journaledwithin the carrier A on the antifriction bearings and within the carriermay be contained a lubricant. By the symmetrical disposition of partsand the disposition of the various bearings torque reactions areadvantageously absorbed, torsional stresses are minimi/z d and freeoperation is assured during incie dental rocking movements of thecarrier about the load carryingmembers. While four wheels on a side arethus simultaneously and positively driven from one live axle section itwill be understood that differentiation between the. four wheels on oneside and the four wheels on the other is permitted by the final drivediflt'erential gearing 5. This relationship is maintained regardless ofthe,

relative an o posite si es as the respective wheels adapt.

an eight wheel drive where the four pairs of wheels may have freerelative movement to adapt themselves to the ground conditions whichthey encounter. The advanta es of an eight wheel drive are thusaccomplis ed with the inclusion in the vehlcle of onl a single loadcarryin axle and'two live ax e sections ,and two ve icle s rings betweenthe load j-i carrying axle and t e frame. 'Not only 'does this result inthe fewest possible num r of parts where the advanta es of an eightwheel drive are to be retained ut adds in addition I maximum flexibilityas regards the action 01' the wheels with respect to one another andwith respect to the frame.

The tires shown on the several wheels of the improved drive areillustrated conventionally as of the solid type but it is to beunderstood that under some conditions of service pneumatic tires may beused to even greater advanta e since by their use even better riding quaities are obtained while such improvements as result from the improveddrive mechanism are wholly retained.

From the above description it is apparent that I have designed an ei htwheel traction unit comprising a four w eel unit on. each side of thechassis, presenting an extensive road contact traction area adapted forheavy duty service and a novel drive mechanism associated with said unitwhereby heavy loads may be transported under uneven and so surface roadconditions, and in order to further effectuate the rinciples of my invention, I have desi ne a unique endlesstrack structure adapte to be quickl mounted on each of the four wheel units, w ereby the vehicle isexpeditiously converted from a road vehicle to one of the caterpillar ortrack laying type, further increasing the surface contacting area andrendering it poss ble to transport heavy loads over otherwise 1mpassableroads, and which structure is lllustrated in Figs. 5, 6, 7 and 8 of'thedrawings.

k t k In 5 there 18 shown an endleqs rac ma be expedltlously effected,.and said links D comprising links 30 formed along each of theirlongitudinal edges with projections 31 and providing an extra wide spacemidway the length of the link as at 32. The projections 31 are aperturedand adapted for tenon engagement with similar projections of theadjacent link, the apertures being properly aligned to receive hingepins 33 secured by pins 34 providing a hinged connection between therespective links and the track ar position of the carriers on connectionis provided.

In order'to connect the free ends. of the chain, the final link 35 atone end is secured by pins 33 as heretofore described, and is reduced asat 36 to form the body portion of less thickness than the links properand its face is formed with longitudinally extending female serrations37 adapted to receive the complemental male serrations 38 formed on theunder surface of the complemental link 40, which has its under surfacereduced as at 41, so that the engagin portions of said links 35 and 40.will be substantially the same thickness as the links proper. Said link40.

is secured to the opposite end of the track bypins 33 as heretoforedescribed, and is provided with bolts'42 at each of its ends and olt 43central of the link in alignment with bolts 42 threadedly or otherwisesuitably secured thereto and adapted to extend downwardlyfrom said link.The link 35 is of less length than link 40, so that bolts 42 projectdownwardly adjacent the opposite ends of said link and bolt 43 extendsthrough slot 44 in link 35 and is adapted to receive lock washer '45 andnut 46. An angle clamp 47 is mounted on each of the boltsv42, theextremity of the perpendicular portion contacting the under surface oflink 40 and the end of the lateral portion contacting the under surfaceof link'35, so that tightening of nuts 48 thereon firmly securesthelinks 35 and 40 to ether similar to the tightening of nut 46 wit respectto bolt 43.

It will be observed that when the track D is operatively secured aboutthe wheels B and B and G and C" the bolts 42 will extend by rivets or inany-other well known manner to the under surface of links 30 central oftheir length are'the projections 49 adapted to extend between wheels C,and G" and B and B" efiectually preventing lateral displacement of thetrack from said wheels.

It will be observed that to convert the road vehicle into one of thecaterpillar or track laying type it is but necessary to mount the trackon each four wheel unit, bringing the serrations of links 35 and 40 intoengagement, and whereby the desired tensioning of the track with respectto the four wheel unit loc ed in the desired adjusted position bytightening nuts 46 and 48 as above described.

No further operation is necessary to secure the track about the tractionunit, frictional engagement of the tires of the traction unit with theinner surface of the chain effects laying thereof without the necessityof employing other means, as will be well underthe form of my inventionillustrated in the accompanying drawings and referred to in the abovedescription as the preferred embodiment,is the most eflicient andpractical; yet realizing the conditions concurrent with the ado vary,'Iesire to emphasize that various minor changes in details ofconstruction, proportion and arrangementof within the scope o theappended claims without departing from or sacrificing any of theprinciples of this invention.

Having thus described my invention, what 'I desire protected by LettersPatent is as set forth in the following claims: 7 p

1. In a motor vehiclea load carrying axle,

'a carrier mounted pivotally on the axle at each side of the vehicle,two pairs of wheels mounted on opposite sides of the carrier and of theaxle, respectively, two live axle sections within the load carryingaxle, and means to drive two pairs of wheels at each side of the vehiclefrom one of said live axle sections. 2. In a motor Vehiclea loadcarrying axle,

a carriermounted pivotally on the axle at each side of the vehicle, twopairs of wheels -mounted on opposite sides of the carrier and oftheaxle, res ectively, two live axle sections within the loa carrying axle,and means disposed within each carrier to drive the two pairs of wheelsmounted thereon from the respective live axle sections.

3. In a motor vehicle, eight wheel drive mechanism comprising a loadcarrying axle, carriers supported pivotally. thereon at oppo site sidesof the vehicle, stub axles journaled in the respective-carriers atequidistant points on opposite sides of the load carrying axle, wheelsmounted on said stub axles in pairs on opposite sides of the respectivecarriers,

and means disposed within the load carrying axle and the carriersfor'driving all of said wheels from a single final drive gear.

4. In a motor vehicle, eight wheel drive mechanism therefor including aload carryingaxle, a carrier pivotally mounted thereon at each side ofthe vehicle, each carrier comprising a casing, stub axles journaled inthe casing at opposite sides of the load carrying axle and atequidistant points therefrom, two wheels splinedon each stub axle anddisposed at oppositesides of the casing, and power transmission meansfor the respective stub axles disposed within each casing.

5. In eight wheel drive mechanism of the character set forth, a singleload carrying axle, a carrier at'each end thereof having oppositelyextending aligned tubular sections concentric with the main tubularsections of the said load carrying axle, and means interposed betweenthe load carryingaxle and the proximate-tubular extension on eachcarrier to mount the carriers pivotally on the load carrying axle.-

6. In eight wheel drive mechanism of the tion of my invention willnecessarily v parts may be resorted to I character described, incombination with a single load carrying axle, carriers mounted pivotallyat opposite ends thereof, live axles within the load carrying axleextending into said carriers and disposed on the rocking axes thereof, adrive gear on each live axle mounted within the respective carriers,wheel axles mountedin the respective carriers at opposite sides of thesaid drive gear,.a pair of wheels positioned on opposite sides of a loadcarr mg axle, said wheels being journaled on t e free ends of the wheelaxles and on opposite sides of the respective'carriers, and gearinginterposed between each of the drive gears and the respective wheelaxles, said gearing being mounted within the respective carriers. 7. Ineight wheel drive mechanism of the character described, in combinationwith a single load carrying axle, carriers mounted pivotally at oppositeends thereof, live axles within the load carrying axle extending intosaid carriers and disposed on the rocking axes thereof, a drive gear oneach live axle mounted within the respective carriers, wheel axlesmounted in the respective carriers at opposite sides of the said drivegear, gearing interposed between each of the drive gears and therespective wheel axles, a pair of wheels positioned on oppositesides ofthe load carrying axle, said wheels being journaled on the free ends ofthe wheel axles and on opposite sides of the respective carriers, saidgearing being mounted within the respective carriers, and separateantifriction bearings mounted within the respective carriers for each ofthe gears.

8. In a motor vehicle, an eight wheel driv ifig unit comprising a fourwheel unit on opwheel traction unit, comprising two four wheel units,eachwheel'of said unit being I independent of the others and removableas such, a power'distributing means located substantially central ofeach four wheel unit, and

means for driving said distributor, whereby a balanced distribution ofwheel unit is effected.

10. Ina motor Vehicle, an eight-wheel traction unit comprising twofour-wheel units, each unit embodying fourindependent wheel assembliesremovable as such, a power distributor mounted! substantially central ofeach four-wheel unit, comprising a chain of gearing and means fordriving. said gearing, whereby, a balanced distribution of power to theeight-wheel unit is effected.

11. A driving mechanism for motor \e hicles embodying in combination .adriving shaft, a driven'shaft, and a differential conpower to the eightnection therebetween, and a traction unit composed of two pairs oftraction members, each pair including four independently removable wheelassemblies,and means in connection withthe traction unit and drivenshaft for efl'ecting a balanced transmission of power from-the drivenshaft to the respective four-wheeljmembers of the traction unit.

12.- A driving mechanism for motor vehicles embodying in combination aneightwheel traction unit comprising two pairs of traction wheels oneachside of the chassis, a carrier casing located centrally of eachfourwheel unit and interconnecting said pairs, a driven means. withinsaid casing associated with said pairs, and means for driving saiddriven means, whereby-ya balanced transmission of power to the tractionunit is effected. 1

13. A driving mechanism for motor vehicles, comprising pairs of wheelson each side of the vehicle, a drive shaft common to said pairs andabout which axis they are adapted to oscillate, means for driving saidpairs arranged symmetrically about said axis intermediate said wheelsand interconnecting said pairs and drive shaft, and means for drivingsaid shaft.

14;. A driving mechanism of the character specified comprising incombination a road vehicle, a driving axle arranged transverse of thisvehicle, wheels disposed'in pairs on opposite sides of each extremity ofthe axle, means affording an oscillatory connection between therespective pairs ofwheels and the extremities of the axle with whichthey are associated, and a gearing in connection with the last mentionedmeans and establishing a drive between the axle and said wheels, saidgearing being arranged symmetrically about the axis of oscillation ofsaid. pairs to permit the oscillation thereof about said axis.

This specification signed this 5th day of February, AFD. 1929.

. JOHN WALTER CHRISTIE.

